1. Field of the Invention
The present invention generally relates to a power supply apparatus for an electrosurgical unit, or high frequency surgical equipment.
More specifically, the present invention is directed to an electrosurgical power supply apparatus capable of previously storing electrosurgical-current waveform data and also capable of distinguishably displaying operation modes.
2. Description of the Related Art
In general, an electrosurgical unit has a major function to achieve surgical invasion. There are typical three electrosurgical operation modes: A) COAGULATION B) CUTTING, and C) BLEND (CUTTING and COAGULATION). When a biological body such as a patient is subject to the three operation modes, both variations in a tissue of the biological body and curing histories thereof are identical to each other. There is another merit of such an electrosurgical operation (electrosurgery) that an amount of hemostasis is rather small and blood absorption from wounded portions of a biological body is also low.
Therefore, very recently, electrosurgical units with the above-described merits have been widely utilized in conjunction with electronic endoscope apparatuses so as to perform polypectomy and hemostasis, while observing a body cavity of a biological body by the electronic endoscope apparatus. Accordingly, an electronic endoscope apparatus was aimed to perform diagnosis to a biological body in the initial developing stage of the endoscope apparatus. However, the major purposes of the recently developed endoscope apparatus are to not only diagnose the biological body, but also to cure a lesion within the biological body which has been discovered during the endoscopic examination. In particular, there is an absolute need for executing polypectomy and judging whether this cut polyp is subject to a cancer or not during the recent endoscopic examination. Under such circumstances, an electrosurgical operation has an extreme merit for performing the polypectomy. To cure a lesion of a biological body by way of an electronic endoscope apparatus in conjunction with an electrosurgical unit, a high-frequency electrosurgical current produced from an electrosurgical power supply apparatus is supplied through a forceps channel of an endoscopic scope thereof to a snare of the electrosurgical unit, thereby electrosurgically cutting the lesion between the snare and return electrode.
In accordance with one conventional electrosurgical power supply apparatus, a plurality of monostable multivibrators have been employed in an electrosurgical signal generating unit so as to produce desired high-frequency current waveforms. However, this conventional electrosurgical power supply apparatus has the following drawbacks.
That is, since the monostable multivibrator is generally constructed of a circuit combination between a resistor and a capacitor, and an active element so as to form a high-frequency signal current, desirable signal waveforms are not always produced. In other words, shapes of the output signals from the monostable multivibrator are not always constant even if the values (i.e. time constant) of these resistor and capacitor are preset. Moreover, since plural monomultivibrators are employed to selectively set the sorts of the electrosurgical operations such as cutting and coagulation modes, a lengthy time required for adjusting the time constant setting elements is needed. In addition, a resultant size of an electrosurgical power supply apparatus becomes large if a signal generating unit employs a plurality of monostable multivibrators. Accordingly, there is a problem not to satisfy a need for integrally assembling both the endoscopic apparatus and electrosurgical power supply apparatus within a single unit. Furthermore, as previously described, since the waveforms of the signals produced from the monostable multivibrator signal generators are not always constant in a preselected electrosurgical operation mode, reliabilities of this electrosurgical power supply apparatus become low.
As previously stated, since many proposals have been made to incorporate an electrosurgical power supply apparatus into an electronic endoscope apparatus as a single unit, there are many possibilities to install such a combination unit within narrower medical examination rooms or spaces.
On the other hand, in general, a large quantity of switches, dials, push buttons and the likes are provided on display panels of the conventional electronic endoscope apparatuses. If other switches and dials of the electrosurgical unit are additionally employed on the display panel of the electronic endoscope apparatus, the entire display panel having such switches and dials becomes complex. Furthermore, there is another difficulty, namely there are regulations such as JIS (Japanese Industrial Safety) and IEC to indicate these components based upon the electrosurgical modes in different colors. For instance, the push buttons used for both the cutting and coagulation modes must be colored in yellow and blue, respectively, based on the IEC regulation. As previously described, since the push buttons and switches are provided under complex conditions, it is rather difficult to distinguish these members by colors for any operators of electronic endoscope apparatus equipped with electrosurgical units. More specifically, since these components gradually become dirty after the lapse of time, such color distinguishabilities are considerably deteriorated.
On the other hand, while observing the television monitor of the conventional electronic endoscope apparatus, an operator proceeds with the endoscopic examination. Under such a circumstance, he can hardly check whether or not the correct push buttons are manipulated by him.
The present invention has been made in an attempt to solve the above-described problems belonging to the conventional electrosurgical power supply apparatuses, and therefore has a primary object to provide an electrosurgical power supply apparatus capable of correctly producing desirable high-frequency electrosurgical current waveforms, and also of generating such preferable waveforms under simple operation.
A further object of the present invention is to provide an electrosurgical power supply apparatus capable of preventing erroneous operations of these switch/dial members even in a combination between an electronic endoscope apparatus and this electrosurgical power supply apparatus.